The present invention relates to a method for machining a series of workpieces by means of at least one machining jet.
Various media are used, e.g., fluids, photons and/or gas, in order to generate a machining jet. Said jet does not have a fixed geometry, but forms a kind of dynamic tool, the temporal characteristic of which is variable. If, e.g., the liquid jet is formed from water containing abrasive material, it may occur that the abrasive material is temporarily fed to the water to a reduced extent, and the liquid jet therefore acts on the workpiece with reduced energy. When machining by means of a laser, flame cutting or plasma jet, it may occur, e.g., that molten material precipitates, for example, in the form of beads on the surface of the workpiece. If these beads can be found on a machining area on which the workpiece is still to be machined, the machining jet will act with a different geometry on the workpiece than was intended.
The temporal change of the machining jet can result in that the workpieces are machined with varying quality. The conventional methods require that each workpiece is checked during the final inspection in order to be able to find the ones of lower quality. As a result, the production of the workpieces is relatively complex and results in increased scrap.
In U.S. Pat. No. 7,640,125 B2, a method is described, in which a reference signal is acquired and evaluated in order to perform a quality control when laser welding two plates for instance. No measures are provided for simplifying such a control when a series of several workpieces is to be machined.
U.S. Pat. No. 5,854,744 describes a method for abrasive water jet cutting, in which the pressure in the nozzle is detected and a corresponding signal is fed to the control unit. Also in this method, no measures are provided for simplifying a quality control in a series of workpieces.